Visible-light activated photocatalysts can be deployed for self-cleaning, air and water purification, and many other applications usually without any post-deployment non-renewable energy costs. This is because the photocatalysts are able to decompose pollutants (like dyes, volatile organic compounds and NOx) using available ambient light-like solar radiation or indoor and outdoor lighting. With the anticipated rapid adoption of UV-free indoor lighting (like LEDs and OLEDs), it is important to find ways to deploy visible-light activated photocatalysts in indoor applications, for instance in cleaning room air in domestic, public and commercial spaces especially in confined spaces like aircrafts, public buildings, etc. Moreover, additional applications for antibacterial surfaces and self-cleaning materials can have wide applicability in the food service, transportation, health care and hospitality sectors.